Cleaner fossil fuel: Natural Gas (shale)?

Types of natural gas
Source: http://www.total.com/en/energies-expertise/oil-gas/exploration-production/strategic-sectors/unconventional-gas/presentation/three-main-sources-unconventional-gas

There are a few types of natural gas as shown on the above diagram. In this blog post, I will be focusing on the arguably cleaner fossil fuel – the shale gas.

Let me start with a bit of background on the increasing usage of shale gas to generate electricity. The geographic distribution of shale gas is largely different from other fossil fuel sources. Countries that previously depend on other countries for energy can now become energy independent. These countries are looking into exploiting this source of energy through fracking.

These countries also use lowered greenhouse gas emissions in comparison with coal as a reason for the increasing extraction of shale gas. The shale gas life-cycle emission is found to be 6% lower than conventional natural gas, 23% lower than gasoline and 33% lower than coal. (Burnham et al., 2011) (Life-cycle emission is a technique to assess potential environment impacts associated with the product)  However, concerns are raised with regards to the fugitive methane emissions. This is because methane is largely more potent gas than carbon dioxide. Methane gas in the atmosphere has a Global Warming Potential (GWP) of 72 times more than carbon dioxide in a 20 year period. (IPCC, 2007)

Fracking, the process of extracting shale gas, is also known to impact the environment and health adversely. Fracking is a process of breaking the large rocks deep underground with high pressures and channelling large amounts of chemicals and sand to displace and collect the shale gas. Clearing of land is needed for fracking to take place. In this process, the survival of species in the area is threatened as their habitats are lost. Toxic chemicals that may escape can potentially affect skin, eyes, respiratory and gastrointestinal systems. In addition, fracking also uses large amounts of water which can pose a problem in water scarce areas.

I believe that natural gas can be used as a transitional fuel to cleaner alternative energy given the lowered carbon emissions it arguably releases. In the long run, countries should still look towards alternative energy like solar and wind power which undoubtedly releases less carbon emissions than natural gas. Furthermore, natural gas extraction is also not as green as alternative energy as seen from the adverse impacts on environment and health.

References

ANON (2014) Life Cycle Assessment (LCA). EPA. Available from: http://www.epa.gov/nrmrl/std/lca/lca.html [Accessed 6 September 2015]

BURNHAM, A., HAN, J., CLARK, C., WANG, M., DUNN, J. & PALOU-RIVER, I (2012) Life-Cycle Greenhouse Gas Emissions of Shale Gas, Natural Gas, Coal and Petroleum. Environmental Science & Technology, 46(2), pp. 619-627

PEDUZZI, P. & HARDING, R. (2012) Gas fracking: can we safely squeeze the rocks? UNEP Global Environment Alert Service (GEAS) . Available from: http://www.unep.org/pdf/unep-geas_nov_2012.pdf [Accessed 6 September 2015].

SOLOMON, S., QIN, D., MANNING, M., CHEN, Z., MARQUIS, M., AVERYT, KB., TIGNOR, M., MILLER, HL(eds.) (2015). Climate Change 2007 The Physical Science Basis. 1st ed. [ebook] New York: Cambridge University Press. Available at: http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4_wg1_full_report.pdf [Accessed 6 September 2015].